Contents of this Issue

Navigation

Page 32 of 40

32 CONCRETE COVERED 2017 COATINGSPROMAG.COM
Concrete and Water
that has a high W/CM begins its life cycle at a disadvantage.
Poor consolidation then creates planes of weakness that are
further compounded by poor curing and lack of cover over the
reinforcement. Not only are these latent construction defects
responsible for poor concrete performance that remain
hidden until deterioration occurs, they compound with the
environmental exposure of concrete and inevitable damage to
the structure to cause concrete to under-perform.
Water Keeper
As stated, water is the secret to concrete, contributing to
the durability through the proper W/CM, consolidation,
curing, and corrosion protection. After the concrete has
been properly placed and cured, the second part of successful
concrete is to keep the water out of the concrete.
Nearly all deterioration mechanisms of concrete involve
water being present or absent at the appropriate times in the
life of the concrete, as well as water ingress being responsi-
ble for property damage from leaking roofs and windows.
Deterioration from freezing and thawing cycles, ingress of
deleterious chemicals, corrosion, and chemical attack do
not occur in dry concrete. Entire industries have developed
materials to keep water out of concrete, such as coatings
manufacturers, membrane applications, sealants production,
water stops, and other specialty treatments. We also know
that application of these protective systems requires a sound
substrate and that application after deterioration initiates is
usually less durable than preventative proactive measures.
Maintenance and inspection can provide triggers for less
expensive and more effective treatments applied before too
much damage has been done.
In short, keep the water in when needed for hydration,
consolidation, and curing, then keep the water out for the
longest life of concrete. CP
Fred Goodwin, EB Const r uct ion Chemica ls Globa l Cor rosion Competenc y
Center Head , is a chemist w it h 30+ years in t he const r uct ion chemica ls
indust r y. He is a fel low of A STM , A mer ican Concrete Inst it ute (ACI), and
Inter nat iona l Concrete Repa ir Inst it ute (ICR I), and he is an honorar y member
of A STM C1 & C9. Goodw in is t he cur rent cha ir of t he ICR I Technica l Act iv it ies
Committee (TAC), ACI 090 TR RC, and Societ y for Protect ive Coat ings (SSPC)
8 . 3 Commercia l Floor Coat ings. He was awarded t he A STM Award of Mer it in
2016, t he Journal of Coatings and Protective Linings' Ed itors Award (2006, 2010,
and 2012), t he ACI 2011 Delmar Bloem Dist ing u ished Ser v ice Award , and
St rateg ic Development Counci l — 2015 Jean-C laude Rouma in Innovat ion
in Concrete Award . For more infor mat ion, contact: BA SF 's Const r uct ion
Chemica ls, w w w.master-bu i lders-solut ions.basf.us/en-us
Improper curing is another latent construction defect. Water needs to
be present during hydration period. Without it, the result could be low
strength and poor durability.
Once cracking occurs in concrete, further deterioration is accelerated.
Other materials can move through the cracks and potentially reach
the steel rebar.
Too much water in concrete can be the cause of concrete's poor
performance. If the water to cementitious material (W/CM) ratio is
off, it can be a problem.